Robert A. Bilott, an Ohio attorney who has taken on DuPont and other manufacturers of a hazardous chemical that's polluted water supplies across the country, is urging a congressional committee to expand its investigation in Hoosick Falls and probe the U.S. Environmental Protection Agency's actions on the contaminant.

Bilott, who helps represent an estimated 3,500 people in a class-action lawsuit against DuPont, which manufactured and used the chemical PFOA in its products, has written a letter to the U.S. House Committee on Oversight and Government Reform saying the arguable mishandling of a water-pollution crisis in eastern Rensselaer County follows years of neglect by the EPA on the issue.

"It is unfortunate that it has taken all these years for people to learn that they have been drinking PFOA and to receive any guidance from EPA as to the safety of long-term exposures to that chemical," Bilott said.

Bilott's request comes after the congressional committee sent letters July 6 to Gov. Andrew Cuomo and EPA Administrator Gina McCarthy requesting they turn over documents related to their agencies' responses to PFOA contamination of public water supplies in eastern Rensselaer County.

The committee cited Times Union articles and other news reports documenting that officials at all levels of government, including the state and Rensselaer County Health departments as well as the EPA, were aware for more than a year that the hazardous chemical, PFOA, had polluted the Hoosick Falls village water system but did not warn residents to stop drinking the water.

State officials later acknowledged the unregulated contaminant also was found in water supplies in nearby Petersburgh.

For more than a decade, Bilott has urged the EPA and federal authorities to investigate and address health threats from having PFOA in drinking water.

"Although we understand that the developments in Hoosick Falls since 2014 are what triggered the committee's current investigation, EPA's delay in responding to PFOA drinking water contamination issues extends far beyond Hoosick Falls and well beyond the events of the last two years," Bilott wrote in his letter.

Bilott said the committee did not acknowledge his request, which was accompanied by copies of dozens of documents and letters he wrote to the EPA and other federal agencies dating back years. Bilott noted he first asked the EPA in March 2001 to investigate widespread PFOA contamination of public water supplies.

"We continued, repeatedly, to press EPA to take appropriate action in this regard as more and more PFOA contamination was discovered between 2001 and 2006 in drinking water supplies in West Virginia, Ohio, Minnesota, and New Jersey, leading to significantly elevated PFOA blood levels in the residents drinking that water," Bilott wrote.

In May, the EPA issued a lifetime drinking water health advisory of 70 parts per trillion for human exposure to the man-made chemical, perfluorooctanoic acid, or PFOA. Six public water systems in New York, including two in Rensselaer County, have detected PFOA in their supplies in excess of the EPA's new guidance standard.

Hoosick Falls' system recorded levels at more than 600 ppt in August 2014, and the chemical also has been found in dozens of private wells in that area.

The non-enforceable EPA advisory came after the agency had issued a short-term exposure guideline of 400 ppt in 2009. The EPA has endured criticism, including from Bilott, for taking years to issue a long-term health advisory for exposure to PFOA and other perfluorinated chemicals that have been used in manufacturing for decades.

Bilott said the EPA retreated from investigating PFOA contamination, or setting a national guideline, after it reached an agreement with manufacturers in 2006 that they would phase out their use of the chemical by last year.

The EPA's 2006 agreement with DuPont and other manufacturers came a year after DuPont agreed to pay $10.25 million in civil penalties to settle a complaint brought by the EPA over the company's PFOA pollution in the Midwest.

A House Oversight committee spokesman did not respond to a request for comment. The EPA also declined comment.

The Times Union first reported in February the state Health Department was made aware in August 2014 that the toxic chemical had contaminated Hoosick Falls' system, but conflicting information and a lack of regulations led to months of delays in notifying the public about the issue, documents show.

The EPA was informed of the water pollution in Hoosick Falls in December 2014, according to emails previously obtained by the Times Union. In December 2015, EPA Regional Administrator Judith Enck sent a letter to Hoosick Falls Mayor David Borge directing him to stop telling residents it was a "personal choice" whether to drink the contaminated water. Borge has said he was relying on advice from the state Health Department.

U.S. Rep. Chris Gibson urged the House committee to investigate and hold hearings on the situation in Hoosick Falls and Petersburgh.

The state's awareness of the contamination actually dates back years. The Times Union reported five months ago that Taconic, a plastics company in Petersburgh, alerted the Department of Environmental Conservation in 2005 about its discovery of the chemical in the groundwater around its Route 22 plant. State officials said environmental laws and regulations in 2005 did not require any public notification or more investigation.

PFOA is a toxic chemical used since the 1940s to make industrial and household products. Several small manufacturers in eastern Rensselaer County and North Bennington, Vt., used the chemical for decades.